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Cardon I, Grobecker S, Jenne F, Jahner T, Rupprecht R, Milenkovic VM, Wetzel CH. Serotonin effects on human iPSC-derived neural cell functions: from mitochondria to depression. Mol Psychiatry 2024:10.1038/s41380-024-02538-0. [PMID: 38532010 DOI: 10.1038/s41380-024-02538-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/13/2024] [Accepted: 03/15/2024] [Indexed: 03/28/2024]
Abstract
Depression's link to serotonin dysregulation is well-known. The monoamine theory posits that depression results from impaired serotonin activity, leading to the development of antidepressants targeting serotonin levels. However, their limited efficacy suggests a more complex cause. Recent studies highlight mitochondria as key players in depression's pathophysiology. Mounting evidence indicates that mitochondrial dysfunction significantly correlates with major depressive disorder (MDD), underscoring its pivotal role in depression. Exploring the serotonin-mitochondrial connection, our study investigated the effects of chronic serotonin treatment on induced-pluripotent stem cell-derived astrocytes and neurons from healthy controls and two case study patients. One was a patient with antidepressant non-responding MDD ("Non-R") and another had a non-genetic mitochondrial disorder ("Mito"). The results revealed that serotonin altered the expression of genes related to mitochondrial function and dynamics in neurons and had an equalizing effect on calcium homeostasis in astrocytes, while ATP levels seemed increased. Serotonin significantly decreased cytosolic and mitochondrial calcium in neurons. Electrophysiological measurements evidenced that serotonin depolarized the resting membrane potential, increased both sodium and potassium current density and ultimately improved the overall excitability of neurons. Specifically, neurons from the Non-R patient appeared responsive to serotonin in vitro, which seemed to improve neurotransmission. While it is unclear how this translates to the systemic level and AD resistance mechanisms are not fully elucidated, our observations show that despite his treatment resistance, this patient's cortical neurons are responsive to serotonergic signals. In the Mito patient, evidence suggested that serotonin, by increasing excitability, exacerbated an existing hyperexcitability highlighting the importance of considering mitochondrial disorders in patients with MDD, and avoiding serotonin-increasing medication. Taken together, our findings suggested that serotonin positively affects calcium homeostasis in astrocytes and increases neuronal excitability. The latter effect must be considered carefully, as it could have beneficial or detrimental implications based on individual pathologies.
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Affiliation(s)
- Iseline Cardon
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053, Regensburg, Germany
| | - Sonja Grobecker
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053, Regensburg, Germany
| | - Frederike Jenne
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053, Regensburg, Germany
| | - Tatjana Jahner
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053, Regensburg, Germany
| | - Rainer Rupprecht
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053, Regensburg, Germany
| | - Vladimir M Milenkovic
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053, Regensburg, Germany
| | - Christian H Wetzel
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053, Regensburg, Germany.
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Cardon I, Grobecker S, Kücükoktay S, Bader S, Jahner T, Nothdurfter C, Koschitzki K, Berneburg M, Weber BHF, Stöhr H, Höring M, Liebisch G, Braun F, Rothammer-Hampl T, Riemenschneider MJ, Rupprecht R, Milenkovic VM, Wetzel CH. Mitochondrial and Cellular Function in Fibroblasts, Induced Neurons, and Astrocytes Derived from Case Study Patients: Insights into Major Depression as a Mitochondria-Associated Disease. Int J Mol Sci 2024; 25:963. [PMID: 38256041 PMCID: PMC10815943 DOI: 10.3390/ijms25020963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/04/2024] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
The link between mitochondria and major depressive disorder (MDD) is increasingly evident, underscored both by mitochondria's involvement in many mechanisms identified in depression and the high prevalence of MDD in individuals with mitochondrial disorders. Mitochondrial functions and energy metabolism are increasingly considered to be involved in MDD's pathogenesis. This study focused on cellular and mitochondrial (dys)function in two atypical cases: an antidepressant non-responding MDD patient ("Non-R") and another with an unexplained mitochondrial disorder ("Mito"). Skin biopsies from these patients and controls were used to generate various cell types, including astrocytes and neurons, and cellular and mitochondrial functions were analyzed. Similarities were observed between the Mito patient and a broader MDD cohort, including decreased respiration and mitochondrial function. Conversely, the Non-R patient exhibited increased respiratory rates, mitochondrial calcium, and resting membrane potential. In conclusion, the Non-R patient's data offered a new perspective on MDD, suggesting a detrimental imbalance in mitochondrial and cellular processes, rather than simply reduced functions. Meanwhile, the Mito patient's data revealed the extensive effects of mitochondrial dysfunctions on cellular functions, potentially highlighting new MDD-associated impairments. Together, these case studies enhance our comprehension of MDD.
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Affiliation(s)
- Iseline Cardon
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany; (I.C.)
| | - Sonja Grobecker
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany; (I.C.)
| | - Selin Kücükoktay
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany; (I.C.)
| | - Stefanie Bader
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany; (I.C.)
| | - Tatjana Jahner
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany; (I.C.)
| | - Caroline Nothdurfter
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany; (I.C.)
| | - Kevin Koschitzki
- Department of Dermatology, Regensburg University Hospital, 93053 Regensburg, Germany
| | - Mark Berneburg
- Department of Dermatology, Regensburg University Hospital, 93053 Regensburg, Germany
| | - Bernhard H. F. Weber
- Institute of Human Genetics, University of Regensburg, 93053 Regensburg, Germany
- Institute of Clinical Human Genetics, Regensburg University Hospital, 93053 Regensburg, Germany
| | - Heidi Stöhr
- Institute of Human Genetics, University of Regensburg, 93053 Regensburg, Germany
| | - Marcus Höring
- Institute of Clinical Chemistry and Laboratory Medicine, Regensburg University Hospital, 93053 Regensburg, Germany
| | - Gerhard Liebisch
- Institute of Clinical Chemistry and Laboratory Medicine, Regensburg University Hospital, 93053 Regensburg, Germany
| | - Frank Braun
- Department of Neuropathology, Regensburg University Hospital, 93053 Regensburg, Germany
| | - Tanja Rothammer-Hampl
- Department of Neuropathology, Regensburg University Hospital, 93053 Regensburg, Germany
| | | | - Rainer Rupprecht
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany; (I.C.)
| | - Vladimir M. Milenkovic
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany; (I.C.)
| | - Christian H. Wetzel
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany; (I.C.)
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Carmona Alexandrino H, Ferreira MA, Ramalho D, Jesus NR, Oliveira MJ. Endocrine Challenges in Myoclonic Epilepsy With Ragged Red Fibers Syndrome: A Case Report. Cureus 2023; 15:e51114. [PMID: 38274904 PMCID: PMC10810140 DOI: 10.7759/cureus.51114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/26/2023] [Indexed: 01/27/2024] Open
Abstract
Myoclonic epilepsy with ragged red fibers (MERRF) syndrome is a primary mitochondrial disorder characterized by myoclonus, epilepsy, ataxia, and muscle fiber abnormalities. While traditionally associated with neurological features, MERRF's multisystem nature extends to endocrine dysfunction, including diabetes mellitus, thyroid disorders, and adrenal abnormalities. This case report explores the multifaceted nature of MERRF syndrome by presenting the clinical journey of a 70-year-old woman who sought care at the endocrinology clinic due to coexisting Addison's disease and diabetes mellitus, marked by recurrent hypoglycemia and suboptimal metabolic control. Over time, she developed a history of myoclonic epilepsy, effectively managed with lamotrigine, along with mild sensory axonal polyneuropathy and ataxia. The patient was diagnosed with MERRF syndrome following her son's diagnosis, which had a severe form. This case underscores the intricate interplay between mitochondrial dysfunction and endocrine manifestations in MERRF syndrome, highlighting the importance of a comprehensive and multidisciplinary approach to patient care. MERRF syndrome's array of endocrine manifestations substantially impacts patients' quality of life and morbidity. A comprehensive approach, uniting endocrinologists, neurologists, geneticists, and other specialists, is essential for effective patient care. Further research is warranted to unravel the complex mitochondrial-endocrine interactions in MERRF syndrome, offering potential insights for improved management.
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Affiliation(s)
| | - Marta A Ferreira
- Department of Endocrinology, Centro Hospitalar de Vila Nova de Gaia/Espinho, EPE, Vila Nova de Gaia, PRT
| | - Diogo Ramalho
- Department of Endocrinology, Centro Hospitalar de Vila Nova de Gaia/Espinho, EPE, Vila Nova de Gaia, PRT
| | - Nuno R Jesus
- Cancer Signalling & Metabolism, Instituto de Investigação e Inovação em Saúde da Universidade do Porto (i3S), Porto, PRT
- Department of Endocrinology, Centro Hospitalar de Vila Nova de Gaia/Espinho, EPE, Vila Nova de Gaia, PRT
| | - Maria J Oliveira
- Department of Endocrinology, Centro Hospitalar de Vila Nova de Gaia/Espinho, EPE, Vila Nova de Gaia, PRT
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Genetics of mitochondrial diseases: Current approaches for the molecular diagnosis. HANDBOOK OF CLINICAL NEUROLOGY 2023; 194:141-165. [PMID: 36813310 DOI: 10.1016/b978-0-12-821751-1.00011-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Mitochondrial diseases are a genetically and phenotypically variable set of monogenic disorders. The main characteristic of mitochondrial diseases is a defective oxidative phosphorylation. Both nuclear and mitochondrial DNA encode the approximately 1500 mitochondrial proteins. Since identification of the first mitochondrial disease gene in 1988 a total of 425 genes have been associated with mitochondrial diseases. Mitochondrial dysfunctions can be caused both by pathogenic variants in the mitochondrial DNA or the nuclear DNA. Hence, besides maternal inheritance, mitochondrial diseases can follow all modes of Mendelian inheritance. The maternal inheritance and tissue specificity distinguish molecular diagnostics of mitochondrial disorders from other rare disorders. With the advances made in the next-generation sequencing technology, whole exome sequencing and even whole-genome sequencing are now the established methods of choice for molecular diagnostics of mitochondrial diseases. They reach a diagnostic rate of more than 50% in clinically suspected mitochondrial disease patients. Moreover, next-generation sequencing is delivering a constantly growing number of novel mitochondrial disease genes. This chapter reviews mitochondrial and nuclear causes of mitochondrial diseases, molecular diagnostic methodologies, and their current challenges and perspectives.
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Fine AL, Liebo G, Gavrilova RH, Britton JW. Seizure Semiology, EEG, and Imaging Findings in Epilepsy Secondary to Mitochondrial Disease. Front Neurol 2021; 12:779052. [PMID: 34912288 PMCID: PMC8666417 DOI: 10.3389/fneur.2021.779052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 10/28/2021] [Indexed: 11/27/2022] Open
Abstract
Background: Identification of an underlying mitochondrial disorder can be challenging due to the significant phenotypic variability between and within specific disorders. Epilepsy can be a presenting symptom with several mitochondrial disorders. In this study, we evaluated clinical, electrophysiologic, and imaging features in patients with epilepsy and mitochondrial disorders to identify common features, which could aid in earlier identification of a mitochondrial etiology. Methods: This is a retrospective case series from January 2011 to December 2019 at a tertiary referral center of patients with epilepsy and a genetically confirmed diagnosis of a mitochondrial disorder. A total of 164 patients were reviewed with 20 patients fulfilling inclusion criteria. Results: A total of 20 patients (14 females, 6 males) aged 0.5-61 years with epilepsy and genetically confirmed mitochondrial disorders were identified. Status epilepticus occurred in 15 patients, with focal status epilepticus in 13 patients, including 9 patients with visual features. Abnormalities over the posterior cerebral regions were seen in 66% of ictal recordings and 44% of imaging studies. All the patients were on nutraceutical supplementation with no significant change in disease progression seen. At last follow-up, eight patients were deceased and the remainder had moderate-to-severe disability. Discussion: In this series of patients with epilepsy and mitochondrial disorders, we found increased propensity for seizures arising from the posterior cerebral regions. Over time, electroencephalogram (EEG) and imaging abnormalities increasingly occurred over the posterior cerebral regions. Focal seizures and focal status epilepticus with visual symptoms were common. Additional study is needed on nutraceutical supplementation in mitochondrial disorders.
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Affiliation(s)
- Anthony L. Fine
- Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Greta Liebo
- Department of Radiology, Mayo Clinic, Rochester, MN, United States
| | - Ralitza H. Gavrilova
- Department of Neurology, Mayo Clinic, Rochester, MN, United States
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, United States
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Waliszewska-Prosół M, Bladowska J, Ejma M, Koziorowska-Gawron E, Budrewicz S. Brain Magnetic Resonance Imaging Findings in Patients with Myoclonus Epilepsy Associated with Ragged-Red Fibers: A 6-Year Follow-Up Study. Neurol India 2021; 69:1121-1122. [PMID: 34507478 DOI: 10.4103/0028-3886.325340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
| | - Joanna Bladowska
- Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw Medical University, Wroclaw, Poland
| | - Maria Ejma
- Department of Neurology, Wroclaw Medical University, Wroclaw, Poland
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Mitochondrial Dysfunction in Diseases, Longevity, and Treatment Resistance: Tuning Mitochondria Function as a Therapeutic Strategy. Genes (Basel) 2021; 12:genes12091348. [PMID: 34573330 PMCID: PMC8467098 DOI: 10.3390/genes12091348] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 01/31/2023] Open
Abstract
Mitochondria are very important intracellular organelles because they have various functions. They produce ATP, are involved in cell signaling and cell death, and are a major source of reactive oxygen species (ROS). Mitochondria have their own DNA (mtDNA) and mutation of mtDNA or change the mtDNA copy numbers leads to disease, cancer chemo/radioresistance and aging including longevity. In this review, we discuss the mtDNA mutation, mitochondrial disease, longevity, and importance of mitochondrial dysfunction in cancer first. In the later part, we particularly focus on the role in cancer resistance and the mitochondrial condition such as mtDNA copy number, mitochondrial membrane potential, ROS levels, and ATP production. We suggest a therapeutic strategy employing mitochondrial transplantation (mtTP) for treatment-resistant cancer.
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Esterhuizen K, Lindeque JZ, Mason S, van der Westhuizen FH, Rodenburg RJ, de Laat P, Smeitink JAM, Janssen MCH, Louw R. One mutation, three phenotypes: novel metabolic insights on MELAS, MIDD and myopathy caused by the m.3243A > G mutation. Metabolomics 2021; 17:10. [PMID: 33438095 DOI: 10.1007/s11306-020-01769-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 12/31/2020] [Indexed: 12/19/2022]
Abstract
INTRODUCTION The m.3243A > G mitochondrial DNA mutation is one of the most common mitochondrial disease-causing mutations, with a carrier rate as high as 1:400. This point mutation affects the MT-TL1 gene, ultimately affecting the oxidative phosphorylation system and the cell's energy production. Strikingly, the m.3243A > G mutation is associated with different phenotypes, including mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), maternally inherited diabetes and deafness (MIDD) and myopathy. OBJECTIVES We investigated urine metabolomes of MELAS, MIDD and myopathy patients in order to identify affected metabolic pathways and possible treatment options. METHODS A multiplatform metabolomics approach was used to comprehensively analyze the metabolome and compare metabolic profiles of different phenotypes caused by the m.3243A > G mutation. Our analytical array consisted of NMR spectroscopy, LC-MS/MS and GC-TOF-MS. RESULTS The investigation revealed phenotypic specific metabolic perturbations, as well as metabolic similarities between the different phenotypes. We show that glucose metabolism is highly disturbed in the MIDD phenotype, but not in MELAS or myopathy, remodeled fatty acid oxidation is characteristic of the MELAS patients, while one-carbon metabolism is strongly modified in both MELAS and MIDD, but not in the myopathy group. Lastly we identified increased creatine in the urine of the myopathy patients, but not in MELAS or MIDD. CONCLUSION We conclude by giving novel insight on the phenotypes of the m.3243A > G mutation from a metabolomics point of view. Directives are also given for future investigations that could lead to better treatment options for patients suffering from this debilitating disease.
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Affiliation(s)
- Karien Esterhuizen
- Mitochondria Research Laboratory, Human Metabolomics, North-West University, Potchefstroom, South Africa
| | - J Zander Lindeque
- Mitochondria Research Laboratory, Human Metabolomics, North-West University, Potchefstroom, South Africa
| | - Shayne Mason
- Mitochondria Research Laboratory, Human Metabolomics, North-West University, Potchefstroom, South Africa
| | | | - Richard J Rodenburg
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Paul de Laat
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Jan A M Smeitink
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Mirian C H Janssen
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
- Department of Internal Medicine, Radboud Center for Mitochondrial Medicine, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Roan Louw
- Mitochondria Research Laboratory, Human Metabolomics, North-West University, Potchefstroom, South Africa.
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University, Potchefstroom Campus, Private Bag X6001, Potchefstroom, South Africa.
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Kaur R, Balaini N, Sharma S, Sharma SK. Lafora body disease: a case of progressive myoclonic epilepsy. BMJ Case Rep 2020; 13:e236971. [PMID: 33370974 PMCID: PMC7757443 DOI: 10.1136/bcr-2020-236971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/02/2020] [Indexed: 12/24/2022] Open
Abstract
Progressive myoclonic epilepsy (PME) is a progressive neurological disorder. Unfortunately, until now, no definitive curative treatment exists; however, it is of utmost importance to identify patients with PME. The underlying aetiology can be pinpointed if methodological clinical evaluation is performed, followed by subsequent genetic testing. We report a case of PME that was diagnosed as Lafora body disease. This case emphasises that, suspecting and identifying PME is important so as to start appropriate treatment and reduce the probability of morbidity and prognosticate the family.
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Affiliation(s)
- Ranjot Kaur
- Medicine, Indira Gandhi Medical College, Shimla, India
| | | | - Sudhir Sharma
- Neurology, Indira Gandhi Medical College, Shimla, India
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Hou Y, Zhao XT, Xie ZY, Yuan Y, Wang ZX. [Mitochondrial encephalopathy, lactic acidosis and stroke-like episodes / myoclonus epilepsy with ragged-red fibers /Leigh overlap syndrome caused by mitochondrial DNA 8344A>G mutation]. BEIJING DA XUE XUE BAO. YI XUE BAN = JOURNAL OF PEKING UNIVERSITY. HEALTH SCIENCES 2020. [PMID: 33047718 DOI: 10.19723/j.issn.1671-167x.2020.05.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Mitochondrial deoxyribonucleic acid (mtDNA) 8344 A>G (m.8344A>G) mutation is the common mutation associated with mitochondrial myoclonus epilepsy with ragged-red fibers (MERRF) syndrome. Herein we report a rare case with mitochondrial encephalopathy, lactic acidosis and stroke-like episodes/MERRF/Leigh (MELAS/MERRF/Leigh) overlap syndrome caused by m.8344A>G mutation. METHODS The clinical and imaging data of the patient were collected and an open muscle biopsy was carried out. We further employed molecular genetic analyses to detect mtDNA mutation in the proband and his mother. And then a clinical and neuroimaging follow-up was performed. RESULTS This patient was a 25-year-old male, who developed exercise intolerance since the age of 6. At age 10, he suffered from acute episodes of hemianopia, and cranial magnetic resonance imaging (MRI) showed occipital stroke-like lesions and cranial magnetic resonance spectroscopy (MRS) revealed a lactate peak corresponding to the lesion. After that the patient presented slowly progressive psychomotor decline. He had myoclonic seizures and cerebellar ataxia since the age of 12. At age 21, he was admitted to our hospital because of confusion and cranial MRI revealed symmetrical lesions in bilateral posterior putamen, thalami and midbrain. Then repeated MRI showed progression of original lesions and new frontal multiple stroke-like lesions. Symptomatic and rehabilitation treatment relieved his condition. Follow-up cranial MRI at age 24 showed the lesions in basal ganglia and thalami diminished, and the midbrain lesions even completely vanished. Muscle pathology indicated the presence of numerous scattered ragged-red fibers (RRF), suggestive of a mitochondrial disorder. Polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP) detected the m.8344A>G mutation of the MT-TK gene encoding mitochondrial transfer RNA for lysine in the patient's blood. Next generation sequencing (NGS) of the whole mitochondrial genome identified that the proportion of m.8344A>G was 90%, and no other mtDNA mutation was detected. Sanger sequencing further identified this mutation both in the proband and his mother's blood, although the mutation load was much lower in his mother's blood with approximately 10% heteroplasmy. CONCLUSION The present study is the first to describe a patient with m.8344A>G mutation in association with the MELAS/MERRF/Leigh overlap syndrome, which expands the phenotypic spectrum of the m.8344A>G mutation.
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Michaud M, Stojkovic T, Maisonobe T, Behin A, Rucheton B, Léonard-Louis S, Eymard B, Laforêt P. Ganglionopathies Associated with MERRF Syndrome: An Original Report. J Neuromuscul Dis 2020; 7:419-423. [DOI: 10.3233/jnd-200513] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Neuropathies in Myoclonic Epilepsy with Ragged Red Fibers (MERRF) syndrome are frequent but ganglionopathies have never been reported. We retrospectively identified 24 patients with MERRF mutations in the neuromuscular center Nord/Est/Ile de France (Pitié-Salpêtrière, Paris, France). Seventeen nerve conduction studies (NCS) were available. Five patients had MERRF syndrome and ganglionopathy, a pure sensory neuropathy. All of them displayed ataxia and mild clinical sensory abnormalities. Ganglionopathies have been reported in mitochondrial diseases but never in MERRF syndrome. We suggest that patients presenting with ganglionopathy, especially if associated with myopathy, lipomatosis or epilepsy, should be screened for MERRF mutations.
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Affiliation(s)
- Maud Michaud
- Department of Neurology, Central Hospital, Neuromuscular Reference Center Nord/Est/Ile de France, Nancy, France
| | - Tanya Stojkovic
- Institute of Myology, Neuromuscular Reference Center Nord/Est/Ile de France, AP-HP, Pitié-Salpêtrière Hospital, Sorbonne University, Paris, France
| | - Thierry Maisonobe
- Department of Neurophysiology and Neuropathology, AP-HP, Pitié-Salpêtrière Hospital, Sorbonne University, Paris, France
| | - Anthony Behin
- Institute of Myology, Neuromuscular Reference Center Nord/Est/Ile de France, AP-HP, Pitié-Salpêtrière Hospital, Sorbonne University, Paris, France
| | - Benoit Rucheton
- Department of Metabolic Biochemistry, AP-HP, Pitié-Salpêtrière Hospital, Sorbonne University, Paris, France
| | - Sarah Léonard-Louis
- Institute of Myology, Neuromuscular Reference Center Nord/Est/Ile de France, AP-HP, Pitié-Salpêtrière Hospital, Sorbonne University, Paris, France
| | - Bruno Eymard
- Institute of Myology, Neuromuscular Reference Center Nord/Est/Ile de France, AP-HP, Pitié-Salpêtrière Hospital, Sorbonne University, Paris, France
| | - Pascal Laforêt
- Department of Neurology, Neuromuscular Reference Center Nord/Est/Ile de France, Raymond-Poincaré Teaching Hospital, AP-HP, Garches, Paris Saclay University, France
- INSERM U1179, END-ICAP Versailles Saint-Quentin-en-Yvelines University
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Roper T, Harber M, Jones G, Pitceathly RDS, Salama AD. Delayed diagnoses of mitochondrial cytopathies in patients presenting with end stage kidney disease: two case reports. BMC Nephrol 2020; 21:361. [PMID: 32838736 PMCID: PMC7446060 DOI: 10.1186/s12882-020-02002-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Accepted: 08/03/2020] [Indexed: 11/10/2022] Open
Abstract
Background Up to one third of patients on renal replacement programmes have an unknown cause of kidney disease, and the diagnosis may only be established following renal transplantation when the disease recurs or if new extra-renal symptoms develop. Case presentation We present two patients who presented with progressive chronic kidney disease of unknown cause. Both patients underwent successful renal transplantation but subsequently developed multisystem abnormalities, and were ultimately diagnosed with mitochondrial cytopathy 10–15 years following transplantation. Conclusions Mitochondrial cytopathies are rare inborn errors of metabolism that should be considered in adults with renal impairment, especially in those with a family history of kidney or other multisystem disease. The widespread availability of genetic testing provides the potential for earlier diagnoses, thereby enhancing management decisions, anticipation of complications, avoidance of mitotoxic drugs, and informed prognosis prediction.
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Affiliation(s)
- Tayeba Roper
- Department of Renal Medicine, Guy's & St Thomas' NHS Foundation Trust, Great Maze Pond, London, UK.
| | - Mark Harber
- UCL Department of Renal Medicine, Royal Free Hospital, Pond Street, Hampstead, London, UK
| | - Gareth Jones
- UCL Department of Renal Medicine, Royal Free Hospital, Pond Street, Hampstead, London, UK
| | - Robert D S Pitceathly
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Alan D Salama
- UCL Department of Renal Medicine, Royal Free Hospital, Pond Street, Hampstead, London, UK
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Abstract
The progressive myoclonic epilepsies (PMEs) represent a rare but devastating group of syndromes characterized by epileptic myoclonus, typically action-induced seizures, neurological regression, medically refractory epilepsy, and a variety of other signs and symptoms depending on the specific syndrome. Most of the PMEs begin in children who are developing as expected, with the onset of the disorder heralded by myoclonic and other seizure types. The conditions are considerably heterogenous, but medical intractability to epilepsy, particularly myoclonic seizures, is a core feature. With the increasing use of molecular genetic techniques, mutations and their abnormal protein products are being delineated, providing a basis for disease-based therapy. However, genetic and enzyme replacement or substrate removal are in the nascent stage, and the primary therapy is through antiepileptic drugs. Epilepsy in children with progressive myoclonic seizures is notoriously difficult to treat. The disorder is rare, so few double-blinded, placebo-controlled trials have been conducted in PME, and drugs are chosen based on small open-label trials or extrapolation of data from drug trials of other syndromes with myoclonic seizures. This review discusses the major PME syndromes and their neurogenetic basis, pathophysiological underpinning, electroencephalographic features, and currently available treatments.
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Affiliation(s)
- Gregory L Holmes
- Department of Neurological Sciences, Larner College of Medicine, University of Vermont College of Medicine, Stafford Hall, 118C, Burlington, VT, 05405, USA.
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14
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Villanueva-Paz M, Povea-Cabello S, Villalón-García I, Álvarez-Córdoba M, Suárez-Rivero JM, Talaverón-Rey M, Jackson S, Falcón-Moya R, Rodríguez-Moreno A, Sánchez-Alcázar JA. Parkin-mediated mitophagy and autophagy flux disruption in cellular models of MERRF syndrome. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165726. [PMID: 32061767 DOI: 10.1016/j.bbadis.2020.165726] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 01/16/2020] [Accepted: 02/10/2020] [Indexed: 12/27/2022]
Abstract
Mitochondrial diseases are considered rare genetic disorders characterized by defects in oxidative phosphorylation (OXPHOS). They can be provoked by mutations in nuclear DNA (nDNA) or mitochondrial DNA (mtDNA). MERRF (Myoclonic Epilepsy with Ragged-Red Fibers) syndrome is one of the most frequent mitochondrial diseases, principally caused by the m.8344A>G mutation in mtDNA, which affects the translation of all mtDNA-encoded proteins and therefore impairs mitochondrial function. In the present work, we evaluated autophagy and mitophagy flux in transmitochondrial cybrids and fibroblasts derived from a MERRF patient, reporting that Parkin-mediated mitophagy is increased in MERRF cell cultures. Our results suggest that supplementation with coenzyme Q10 (CoQ), a component of the electron transport chain (ETC) and lipid antioxidant, prevents Parkin translocation to the mitochondria. In addition, CoQ acts as an enhancer of autophagy and mitophagy flux, which partially improves cell pathophysiology. The significance of Parkin-mediated mitophagy in cell survival was evaluated by silencing the expression of Parkin in MERRF cybrids. Our results show that mitophagy acts as a cell survival mechanism in mutant cells. To confirm these results in one of the main affected cell types in MERRF syndrome, mutant induced neurons (iNs) were generated by direct reprogramming of patients-derived skin fibroblasts. The treatment of MERRF iNs with Guttaquinon CoQ10 (GuttaQ), a water-soluble derivative of CoQ, revealed a significant improvement in cell bioenergetics. These results indicate that iNs, along with fibroblasts and cybrids, can be utilized as reliable cellular models to shed light on disease pathomechanisms as well as for drug screening.
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Affiliation(s)
- Marina Villanueva-Paz
- Centro Andaluz de Biología del Desarrollo (CABD-CSIC-Universidad Pablo de Olavide), Spain; Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Spain
| | - Suleva Povea-Cabello
- Centro Andaluz de Biología del Desarrollo (CABD-CSIC-Universidad Pablo de Olavide), Spain; Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Spain
| | - Irene Villalón-García
- Centro Andaluz de Biología del Desarrollo (CABD-CSIC-Universidad Pablo de Olavide), Spain; Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Spain
| | - Mónica Álvarez-Córdoba
- Centro Andaluz de Biología del Desarrollo (CABD-CSIC-Universidad Pablo de Olavide), Spain; Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Spain
| | - Juan M Suárez-Rivero
- Centro Andaluz de Biología del Desarrollo (CABD-CSIC-Universidad Pablo de Olavide), Spain; Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Spain
| | - Marta Talaverón-Rey
- Centro Andaluz de Biología del Desarrollo (CABD-CSIC-Universidad Pablo de Olavide), Spain; Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Spain
| | - Sandra Jackson
- Department of Neurology, Uniklinikum C. G. Carus, Dresden, Germany
| | - Rafael Falcón-Moya
- Laboratorio de Neurociencia Celular y Plasticidad, Departamento de Fisiología, Anatomía y Biología Celular, Universidad Pablo de Olavide, Sevilla 41013, Spain
| | - Antonio Rodríguez-Moreno
- Laboratorio de Neurociencia Celular y Plasticidad, Departamento de Fisiología, Anatomía y Biología Celular, Universidad Pablo de Olavide, Sevilla 41013, Spain
| | - José A Sánchez-Alcázar
- Centro Andaluz de Biología del Desarrollo (CABD-CSIC-Universidad Pablo de Olavide), Spain; Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Spain.
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15
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O'Keefe H, Queen R, Lord P, Elson JL. What can a comparative genomics approach tell us about the pathogenicity of mtDNA mutations in human populations? Evol Appl 2019; 12:1912-1930. [PMID: 31700535 PMCID: PMC6824070 DOI: 10.1111/eva.12851] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 05/13/2019] [Accepted: 07/17/2019] [Indexed: 01/05/2023] Open
Abstract
Mitochondrial disorders are heterogeneous, showing variable presentation and penetrance. Over the last three decades, our ability to recognize mitochondrial patients and diagnose these mutations, linking genotype to phenotype, has greatly improved. However, it has become increasingly clear that these strides in diagnostics have not benefited all population groups. Recent studies have demonstrated that patients from genetically understudied populations, in particular those of black African heritage, are less likely to receive a diagnosis of mtDNA disease. It has been suggested that haplogroup context might influence the presentation and penetrance of mtDNA disease; thus, the spectrum of mutations that are associated with disease in different populations. However, to date there is only one well-established example of such an effect: the increased penetrance of two Leber's hereditary optic neuropathy mutations on a haplogroup J background. This paper conducted the most extensive investigation to date into the importance of haplogroup context on the pathogenicity of mtDNA mutations. We searched for proven human point mutations across 726 multiple sequence alignments derived from 33 non-human species absent of disease. A total of 58 pathogenic point mutations arise in the sequences of these species. We assessed the sequence context and found evidence of population variants that could modulate the phenotypic expression of these point mutations masking the pathogenic effects seen in humans. This supports the theory that sequence context is influential in the presentation of mtDNA disease and has implications for diagnostic practices. We have shown that our current understanding of the pathogenicity of mtDNA point mutations, primarily built on studies of individuals with haplogroups HVUKTJ, will not present a complete picture. This will have the effect of creating a diagnostic inequality, whereby individuals who do not belong to these lineages are less likely to receive a genetic diagnosis.
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Affiliation(s)
- Hannah O'Keefe
- Institute of Genetic MedicineNewcastle UniversityNewcastle‐upon‐TyneUK
- School of ComputingNewcastle UniversityNewcastle‐upon‐TyneUK
| | - Rachel Queen
- Bioinformatics Core FacilityNewcastle UniversityNewcastle‐upon‐TyneUK
| | - Phillip Lord
- School of ComputingNewcastle UniversityNewcastle‐upon‐TyneUK
| | - Joanna L. Elson
- Institute of Genetic MedicineNewcastle UniversityNewcastle‐upon‐TyneUK
- Centre for Human MetabonomicsNorth‐West UniversityPotchefstroomSouth Africa
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16
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Abstract
INTRODUCTION Epilepsy is a prominent feature of myoclonic epilepsy with ragged-red fibers (MERRF)-syndrome. The most frequent seizure type is myoclonic seizures, of which the treatment is challenging and empiric. AREAS COVERED Herein, the author summarises and discusses previous and recent findings of antiepileptic drug (AED) treatment in MERRF-syndrome. EXPERT OPINION MERRF-syndrome is a predominantly maternally inherited, multisystem mitochondrial disorder caused by pathogenic variants predominantly of the mitochondrial DNA (mtDNA). Canonical clinical features of MERRF include myoclonus, epilepsy, ataxia, and myopathy. Additionally, other manifestations in the CNS, peripheral nerves, eyes, ears, heart, gastrointestinal tract, and endocrine organs may occur (MERRF-plus). Today, MERRF is considered rather as myoclonic ataxia than as myoclonic epilepsy. Genotypically, MERRF is due to mutations in 13 mtDNA-located genes and 1 nDNA-located gene. According to the modified Smith-score, the strongest gene-disease relationship exists for MT-TK, MT-TL1, and POLG1. Epilepsy is the second most frequent phenotypic feature of MERRF. Seizure-types associated with MERRF include focal myoclonic, focal clonic, and focal atonic seizures, generalized myoclonic, tonic-clonic, atonic, and myoclonic-atonic seizures, or typical absences. Treatment of myoclonic epilepsy relies on expert judgments recommending levetiracetam, together with clonazepam, or topiramate, zonisamide, or piracetam in monotherapy as the first line AEDs.
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Affiliation(s)
- Josef Finsterer
- a Krankenanstalt Rudolfstiftung , Messerli Institute , Vienna , Austria
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17
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Villanueva-Paz M, Povea-Cabello S, Villalón-García I, Suárez-Rivero JM, Álvarez-Córdoba M, de la Mata M, Talaverón-Rey M, Jackson S, Sánchez-Alcázar JA. Pathophysiological characterization of MERRF patient-specific induced neurons generated by direct reprogramming. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:861-881. [PMID: 30797798 DOI: 10.1016/j.bbamcr.2019.02.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 12/19/2018] [Accepted: 02/15/2019] [Indexed: 12/13/2022]
Abstract
Mitochondrial diseases are a group of rare heterogeneous genetic disorders caused by total or partial mitochondrial dysfunction. They can be caused by mutations in nuclear or mitochondrial DNA (mtDNA). MERRF (Myoclonic Epilepsy with Ragged-Red Fibers) syndrome is one of the most common mitochondrial disorders caused by point mutations in mtDNA. It is mainly caused by the m.8344A > G mutation in the tRNALys (UUR) gene of mtDNA (MT-TK gene). This mutation affects the translation of mtDNA encoded proteins; therefore, the assembly of the electron transport chain (ETC) complexes is disrupted, leading to a reduced mitochondrial respiratory function. However, the molecular pathogenesis of MERRF syndrome remains poorly understood due to the lack of appropriate cell models, particularly in those cell types most affected in the disease such as neurons. Patient-specific induced neurons (iNs) are originated from dermal fibroblasts derived from different individuals carrying the particular mutation causing the disease. Therefore, patient-specific iNs can be used as an excellent cell model to elucidate the mechanisms underlying MERRF syndrome. Here we present for the first time the generation of iNs from MERRF dermal fibroblasts by direct reprograming, as well as a series of pathophysiological characterizations which can be used for testing the impact of a specific mtDNA mutation on neurons and screening for drugs that can correct the phenotype.
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Affiliation(s)
- Marina Villanueva-Paz
- Centro Andaluz de Biología del Desarrollo (CABD-CSIC-Universidad Pablo de Olavide), and Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Sevilla 41013, Spain
| | - Suleva Povea-Cabello
- Centro Andaluz de Biología del Desarrollo (CABD-CSIC-Universidad Pablo de Olavide), and Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Sevilla 41013, Spain
| | - Irene Villalón-García
- Centro Andaluz de Biología del Desarrollo (CABD-CSIC-Universidad Pablo de Olavide), and Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Sevilla 41013, Spain
| | - Juan M Suárez-Rivero
- Centro Andaluz de Biología del Desarrollo (CABD-CSIC-Universidad Pablo de Olavide), and Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Sevilla 41013, Spain
| | - Mónica Álvarez-Córdoba
- Centro Andaluz de Biología del Desarrollo (CABD-CSIC-Universidad Pablo de Olavide), and Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Sevilla 41013, Spain
| | - Mario de la Mata
- Centro Andaluz de Biología del Desarrollo (CABD-CSIC-Universidad Pablo de Olavide), and Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Sevilla 41013, Spain
| | - Marta Talaverón-Rey
- Centro Andaluz de Biología del Desarrollo (CABD-CSIC-Universidad Pablo de Olavide), and Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Sevilla 41013, Spain
| | - Sandra Jackson
- Department of Neurology, Uniklinikum C. G. Carus, Dresden, Germany
| | - José A Sánchez-Alcázar
- Centro Andaluz de Biología del Desarrollo (CABD-CSIC-Universidad Pablo de Olavide), and Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Sevilla 41013, Spain.
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18
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Miyaue N, Yamanishi Y, Tada S, Ando R, Nagai M, Nomoto M. Falling After Starting Running in a Case of Myoclonus Epilepsy Associated with Ragged-red Fibers with a 8344A>G mtDNA Mutation. Intern Med 2018; 57:3439-3443. [PMID: 29984755 PMCID: PMC6306540 DOI: 10.2169/internalmedicine.1210-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Myoclonus epilepsy associated with ragged-red fibers (MERRF) is traditionally characterized by myoclonus, generalized epilepsy and ragged-red fibers. We herein report a 42-year-old man who complained of falling after starting running, symptoms resembling those of paroxysmal kinesigenic dyskinesia. He showed only slight muscle weakness of the right quadriceps femoris. Muscle pathology and a genetic analysis identified him as having MERRF with a 8344A>G mtDNA mutation. We diagnosed his symptoms as having been caused by slight quadriceps femoris muscle weakness and exercise intolerance. This case suggests that mitochondrial myopathy should be considered in cases with strong muscle symptoms for muscle weakness.
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Affiliation(s)
- Noriyuki Miyaue
- Department of Neurology and Clinical Pharmacology, Ehime University Graduate School of Medicine, Japan
| | - Yuki Yamanishi
- Department of Neurology and Clinical Pharmacology, Ehime University Graduate School of Medicine, Japan
| | - Satoshi Tada
- Department of Neurology and Clinical Pharmacology, Ehime University Graduate School of Medicine, Japan
| | - Rina Ando
- Department of Neurology and Clinical Pharmacology, Ehime University Graduate School of Medicine, Japan
| | - Masahiro Nagai
- Department of Neurology and Clinical Pharmacology, Ehime University Graduate School of Medicine, Japan
| | - Masahiro Nomoto
- Department of Neurology and Clinical Pharmacology, Ehime University Graduate School of Medicine, Japan
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19
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Su LJ, Wang YL, Han T, Qiao S, Zang KJ, Wu HK, Su YX, Liu LL, Liu XW. Antimyoclonic Effect of Levetiracetam and Clonazepam Combined Treatment on Myoclonic Epilepsy with Ragged-Red Fiber Syndrome with m.8344A>G Mutation. Chin Med J (Engl) 2018; 131:2433-2438. [PMID: 30334528 PMCID: PMC6202596 DOI: 10.4103/0366-6999.243568] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Treatment of myoclonic seizures in myoclonic epilepsy with ragged-red fibers (MERRFs) has been empirical and ineffective. Guideline on this disease is not available. Additional trials must be conducted to find more suitable treatments for it. In this study, the antimyoclonic effects of monotherapies, including levetiracetam (LEV), clonazepam (CZP), valproic acid (VPA), and topiramate (TPM) compared to combination therapy group with LEV and CZP on MERRF, were evaluated to find a more advantageous approach on the treatment of myoclonic seizures. METHODS Treatments of myoclonic seizures with VPA, LEV, CZP, and TPM were reported as monotherapies in 17 MERRF patients from Qilu Hospital between 2003 and 2016, who were diagnosed through clinical data and genetic testing. After 1-4 months of follow-up (mean: 82.9 ± 28.1 days), 12 patients that exhibited poor responses to monotherapy were given a combined treatment consisting of LEV and CZP subsequently. The follow-up period was 4-144 months (mean: 66.3 ± 45.3 months), the effective rates of monotherapy group (17 patients) and combination therapy group (12 patients) were analyzed by Chi-square test. RESULTS The m.8344 A>G mutation was detected in all patients. There were four patients with partial response (4/17, two in the CZP group and two in the LEV group), ten patients with stable disease (10/17, six in the CZP group, three in the LEV group, and one in the TPM group), and three patients with progressive disease (3/18, two in the VPA group and one in the TPM group). Twelve of the patients with LEV combined with CZP showed a positive effect and good tolerance (12/12), eight of them demonstrated improved cognition and coordination. There was a significant difference between the monotherapy group and combination therapy group in the efficacy of antimyoclonic seizures (χ2 = 13.7, P < 0.001). CONCLUSIONS LEV in combination with CZP is an efficient and safe treatment for myoclonic seizures in patients with this disease exhibiting the m.8344A>G mutation.
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Affiliation(s)
- Li-Jun Su
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, Shandong 251102, China
| | - Yu-Liang Wang
- Department of Neurology, Binzhou Medical University Hospital, Binzhou, Shandong 256603, China
| | - Tao Han
- Department of Neurology, Xuanwu Hospital Capital Medical University, Beijing 100053, China
| | - Shan Qiao
- Department of Neurology, Qianfoshan Hospital of Shandong Province, Jinan, Shandong 250014, China
| | - Ke-Jun Zang
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, Shandong 251102, China
| | - Huai-Kuan Wu
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, Shandong 251102, China
| | - Yong-Xin Su
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, Shandong 251102, China
| | - Ling-Ling Liu
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, Shandong 251102, China
| | - Xue-Wu Liu
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, Shandong 251102, China
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20
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Alternative respiratory chain enzymes: Therapeutic potential and possible pitfalls. Biochim Biophys Acta Mol Basis Dis 2018; 1865:854-866. [PMID: 30342157 DOI: 10.1016/j.bbadis.2018.10.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 10/03/2018] [Accepted: 10/05/2018] [Indexed: 01/07/2023]
Abstract
The alternative respiratory chain (aRC), comprising the alternative NADH dehydrogenases (NDX) and quinone oxidases (AOX), is found in microbes, fungi and plants, where it buffers stresses arising from restrictions on electron flow in the oxidative phosphorylation system. The aRC enzymes are also found in species belonging to most metazoan phyla, including some chordates and arthropods species, although not in vertebrates or in Drosophila. We postulated that the aRC enzymes might be deployed to alleviate pathological stresses arising from mitochondrial dysfunction in a wide variety of disease states. However, before such therapies can be contemplated, it is essential to understand the effects of aRC enzymes on cell metabolism and organismal physiology. Here we report and discuss new findings that shed light on the functions of the aRC enzymes in animals, and the unexpected benefits and detriments that they confer on model organisms. In Ciona intestinalis, the aRC is induced by hypoxia and by sulfide, but is unresponsive to other environmental stressors. When expressed in Drosophila, AOX results in impaired survival under restricted nutrition, in addition to the previously reported male reproductive anomalies. In contrast, it confers cold resistance to developing and adult flies, and counteracts cell signaling defects that underlie developmental dysmorphologies. The aRC enzymes may also influence lifespan and stress resistance more generally, by eliciting or interfering with hormetic mechanisms. In sum, their judicious use may lead to major benefits in medicine, but this will require a thorough characterization of their properties and physiological effects.
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21
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Ryzhkova AI, Sazonova MA, Sinyov VV, Galitsyna EV, Chicheva MM, Melnichenko AA, Grechko AV, Postnov AY, Orekhov AN, Shkurat TP. Mitochondrial diseases caused by mtDNA mutations: a mini-review. Ther Clin Risk Manag 2018; 14:1933-1942. [PMID: 30349272 PMCID: PMC6186303 DOI: 10.2147/tcrm.s154863] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
There are several types of mitochondrial cytopathies, which cause a set of disorders, arise as a result of mitochondria’s failure. Mitochondria’s functional disruption leads to development of physical, growing and cognitive disabilities and includes multiple organ pathologies, essentially disturbing the nervous and muscular systems. The origins of mitochondrial cytopathies are mutations in genes of nuclear DNA encoding mitochondrial proteins or in mitochondrial DNA. Nowadays, numerous mtDNA mutations significant to the appearance and progress of pathologies in humans are detected. In this mini-review, we accent on the mitochondrial cytopathies related to mutations of mtDNA. As well known, there are definite set of symptoms of mitochondrial cytopathies distinguishing or similar for different syndromes. The present article contains data about mutations linked with cytopathies that facilitate diagnosis of different syndromes by using genetic analysis methods. In addition, for every individual, more effective therapeutic approach could be developed after wide-range mutant background analysis of mitochondrial genome.
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Affiliation(s)
- Anastasia I Ryzhkova
- Laboratory of Medical Genetics, National Medical Research Center of Cardiology, Moscow, Russian Federation, .,Department of Virology, K.I. Skryabin Moscow State Academy of Veterinary Medicine and Biotechnology-MVA, Moscow, Russian Federation,
| | - Margarita A Sazonova
- Laboratory of Medical Genetics, National Medical Research Center of Cardiology, Moscow, Russian Federation, .,Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Moscow, Russian Federation
| | - Vasily V Sinyov
- Laboratory of Medical Genetics, National Medical Research Center of Cardiology, Moscow, Russian Federation,
| | - Elena V Galitsyna
- Department of Genetics, Southern Federal University, Rostov-on-Don, Russian Federation
| | - Mariya M Chicheva
- Department of Genetics, Southern Federal University, Rostov-on-Don, Russian Federation
| | | | - Andrey V Grechko
- Federal Research and Clinical Center of Reanimatology and Rehabilitology, Moscow, Russian Federation
| | - Anton Yu Postnov
- Laboratory of Medical Genetics, National Medical Research Center of Cardiology, Moscow, Russian Federation,
| | - Alexander N Orekhov
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Moscow, Russian Federation.,Institute for Atherosclerosis Research, Skolkovo Innovative Centre, Moscow Region, Russian Federation
| | - Tatiana P Shkurat
- Department of Genetics, Southern Federal University, Rostov-on-Don, Russian Federation
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22
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Shen C, Xian W, Zhou H, Li X, Liang X, Chen L. Overlapping Leigh Syndrome/Myoclonic Epilepsy With Ragged Red Fibres in an Adolescent Patient With a Mitochondrial DNA A8344G Mutation. Front Neurol 2018; 9:724. [PMID: 30271374 PMCID: PMC6146370 DOI: 10.3389/fneur.2018.00724] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 08/08/2018] [Indexed: 12/24/2022] Open
Abstract
We present the case of a 16-year-old boy with a family history of epilepsy who presented with acute respiratory failure, limb weakness, diabetes mellitus, sinus tachycardia, lactic acidosis, and pneumonia. He went on to develop cranial nerve palsy, myoclonus, generalized seizures, ataxia, recurrent pneumonia, and hypotension. Biochemical investigation revealed elevated lactate, pyruvate, and glucose levels. Cerebral magnetic resonance imaging (MRI) revealed bilateral, symmetric, high-intensity T2-weighted signals in the thalamus, brainstem, and gray matter of the spinal cord. Histochemical analyses revealed ragged red fibers (RRF) and decreased cytochrome oxidase activity. Blood and muscle-derived DNA demonstrated a high level (95% and 96%, respectively) of the m.8344A>G mutation, while almost all of his maternal relatives (n = 17, including his mother) carried the same point mutation. The point mutation level of his mother (who had short stature, high blood lactate levels, and epilepsy) was 77% (blood-derived DNA). Although this mutation has been identified in approximately 30 individuals with these disorders, to our knowledge, this is the first reported case of overlapping Leigh syndrome/myoclonic epilepsy with RRF in an adolescent patient, and the largest reported pedigree of mitochondrial DNA A8344G mutation.
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Affiliation(s)
- Cunzhou Shen
- Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Wenbiao Xian
- Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Hongyan Zhou
- Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Xunhua Li
- Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Xiuling Liang
- Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Ling Chen
- Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
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23
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Bhat S, Ganesh S. New discoveries in progressive myoclonus epilepsies: a clinical outlook. Expert Rev Neurother 2018; 18:649-667. [DOI: 10.1080/14737175.2018.1503949] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Shweta Bhat
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | - Subramaniam Ganesh
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
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24
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Orsini M, Carolina A, Ferreira ADF, de Assis ACD, Magalhães T, Teixeira S, Bastos VH, Marinho V, Oliveira T, Fiorelli R, Oliveira AB, de Freitas MR. Cognitive impairment in neuromuscular diseases: A systematic review. Neurol Int 2018; 10:7473. [PMID: 30069288 PMCID: PMC6050451 DOI: 10.4081/ni.2018.7473] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/04/2017] [Accepted: 12/12/2017] [Indexed: 12/12/2022] Open
Abstract
Neuromuscular diseases are multifactorial pathologies characterized by extensive muscle fiber damage that leads to the activation of satellite cells and to the exhaustion of their pool, with consequent impairment of neurobiological aspects, such as cognition and motor control. To review the knowledge and obtain a broad view of the cognitive impairment on Neuromuscular Diseases. Cognitive impairment in neuromuscular disease was explored; a literature search up to October 2017 was conducted, including experimental studies, case reports and reviews written in English. Keywords included Cognitive Impairment, Neuromuscular Diseases, Motor Neuron Diseases, Dystrophinopathies and Mitochondrial Disorders. Several cognitive evaluation scales, neuroimaging scans, genetic analysis and laboratory applications in neuromuscular diseases, especially when it comes to the Motor Neuron Diseases, Dystrophinopathies and Mitochondrial Disorders. In addition, organisms model using rats in the genetic analysis and laboratory applications to verify the cognitive and neuromuscular impacts. Several studies indicate that congenital molecular alterations in neuromuscular diseases promote cognitive dysfunctions. Understanding these mechanisms may in the future guide the proper management of the patient, evaluation, establishment of prognosis, choice of treatment and development of innovative interventions such as gene therapy.
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Affiliation(s)
- Marco Orsini
- Master’s Program in Health Applied Sciences, Severino Sombra University, Vasssouras, Rio de Janeiro
- Brain Mapping and Plasticity Laboratory, Federal University of Piauí, Parnaíba
| | | | | | - Anna Carolina Damm de Assis
- Department of Neurology, Federal Fluminense University, Rio de Janeiro
- Department of Neurology, Federal University of São Paulo
| | - Thais Magalhães
- Department of Neurology, Federal Fluminense University, Rio de Janeiro
| | - Silmar Teixeira
- Brain Mapping and Plasticity Laboratory, Federal University of Piauí, Parnaíba
| | - Victor Hugo Bastos
- Brain Mapping and Plasticity Laboratory, Federal University of Piauí, Parnaíba
| | - Victor Marinho
- Brain Mapping and Plasticity Laboratory, Federal University of Piauí, Parnaíba
| | - Thomaz Oliveira
- Brain Mapping and Plasticity Laboratory, Federal University of Piauí, Parnaíba
| | - Rossano Fiorelli
- Master’s Program in Health Applied Sciences, Severino Sombra University, Vasssouras, Rio de Janeiro
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Abstract
BACKGROUND Given the etiologic heterogeneity of disease classification using clinical phenomenology, we employed contemporary criteria to classify variants associated with myoclonic epilepsy with ragged-red fibers (MERRF) syndrome and to assess the strength of evidence of gene-disease associations. Standardized approaches are used to clarify the definition of MERRF, which is essential for patient diagnosis, patient classification, and clinical trial design. METHODS Systematic literature and database search with application of standardized assessment of gene-disease relationships using modified Smith criteria and of variants reported to be associated with MERRF using modified Yarham criteria. RESULTS Review of available evidence supports a gene-disease association for two MT-tRNAs and for POLG. Using modified Smith criteria, definitive evidence of a MERRF gene-disease association is identified for MT-TK. Strong gene-disease evidence is present for MT-TL1 and POLG. Functional assays that directly associate variants with oxidative phosphorylation impairment were critical to mtDNA variant classification. In silico analysis was of limited utility to the assessment of individual MT-tRNA variants. With the use of contemporary classification criteria, several mtDNA variants previously reported as pathogenic or possibly pathogenic are reclassified as neutral variants. CONCLUSIONS MERRF is primarily an MT-TK disease, with pathogenic variants in this gene accounting for ~90% of MERRF patients. Although MERRF is phenotypically and genotypically heterogeneous, myoclonic epilepsy is the clinical feature that distinguishes MERRF from other categories of mitochondrial disorders. Given its low frequency in mitochondrial disorders, myoclonic epilepsy is not explained simply by an impairment of cellular energetics. Although MERRF phenocopies can occur in other genes, additional data are needed to establish a MERRF disease-gene association. This approach to MERRF emphasizes standardized classification rather than clinical phenomenology, thus improving patient diagnosis and clinical trial design.
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Park SY, Kim SH, Lee YM. Molecular Diagnosis of Myoclonus Epilepsy Associated with Ragged-Red Fibers Syndrome in the Absence of Ragged Red Fibers. Front Neurol 2017; 8:520. [PMID: 29033892 PMCID: PMC5626808 DOI: 10.3389/fneur.2017.00520] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 09/19/2017] [Indexed: 11/13/2022] Open
Abstract
Myoclonus epilepsy with ragged-red fibers (MERRFs), an inherited mitochondrial disorder, has characteristic morphological changes of ragged-red fibers (RRFs) in muscle biopsy, in the absence of which mitochondrial etiology is usually not considered in patients with phenotypes suggestive of MERRF. In these circumstances, MERRF can only be diagnosed using genetic analyses. The symptoms, pathological findings, and imaging results being age dependent, we can construct a protocol based on these characteristics to understand the disease’s natural course and to manage patients more effectively. The absence of RRFs should not preclude a MERRF diagnosis.
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Affiliation(s)
- Sun Yeong Park
- Departments of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea
| | - Se Hoon Kim
- Departments of Pathology, Yonsei University College of Medicine, Seoul, South Korea
| | - Young-Mock Lee
- Departments of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea
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Finsterer J, Zarrouk-Mahjoub S. Management of epilepsy in MERRF syndrome. Seizure 2017; 50:166-170. [DOI: 10.1016/j.seizure.2017.06.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 05/26/2017] [Accepted: 06/13/2017] [Indexed: 11/28/2022] Open
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Finsterer J, Habitzl W. Lactose-free diet inducing aseptic pancreatitis and myoclonic jerks in late-onset, putative MERRF syndrome. J Neurol 2016; 263:586-7. [DOI: 10.1007/s00415-016-8028-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 01/08/2016] [Accepted: 01/09/2016] [Indexed: 01/09/2023]
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